1. Field of the Invention
The present invention relates to endoscopic surgical tools which are endoscopically inserted into a body.
2. Description of the Related Art
Endoscopic treatment tools such as a biopsy brush provided with synthetic fibers inserted between a stranded wire have been used conventionally in order to sample tissue from a body which is used for medical tests. When tissue is sampled with the biopsy brush above, tissue is often sampled by rotating the brush section with a rotary operation of a handle disposed at a proximal end of a wire.
However, tissue sampling target sites such as a bile duct have several narrow portions and a friction often exerts between tissue walls and the brush. If the rotary operation above is performed in this case, the wire that rotates though the brush section does not rotate due to the friction, so there is a possibility of breaking the wire upon exerting an excessive torsional load.